#!/usr/bin/python """ redis.py - A client for the Redis daemon. """ __author__ = "Ludovico Magnocavallo " __copyright__ = "Copyright 2009, Ludovico Magnocavallo" __license__ = "MIT" __version__ = "0.5" __revision__ = "$LastChangedRevision: 175 $"[22:-2] __date__ = "$LastChangedDate: 2009-03-17 16:15:55 +0100 (Mar, 17 Mar 2009) $"[18:-2] # TODO: Redis._get_multi_response import socket BUFSIZE = 4096 class RedisError(Exception): pass class ConnectionError(RedisError): pass class ResponseError(RedisError): pass class InvalidResponse(RedisError): pass class InvalidData(RedisError): pass class Redis(object): """The main Redis client. """ def __init__(self, host=None, port=None, timeout=None): self.host = host or 'localhost' self.port = port or 6379 if timeout: socket.setdefaulttimeout(timeout) self._sock = None self._fp = None def _write(self, s): """ >>> r = Redis() >>> r.connect() >>> r._sock.close() >>> try: ... r._write('pippo') ... except ConnectionError, e: ... print e Error 9 while writing to socket. Bad file descriptor. >>> >>> """ try: self._sock.sendall(s) except socket.error, e: if e.args[0] == 32: # broken pipe self.disconnect() raise ConnectionError("Error %s while writing to socket. %s." % tuple(e.args)) def _read(self): try: return self._fp.readline() except socket.error, e: if e.args and e.args[0] == errno.EAGAIN: return self.disconnect() raise ConnectionError("Error %s while reading from socket. %s." % tuple(e.args)) if not data: self.disconnect() raise ConnectionError("Socket connection closed when reading.") return data def ping(self): """ >>> r = Redis() >>> r.ping() 'PONG' >>> """ self.connect() self._write('PING\r\n') return self.get_response() def set(self, name, value, preserve=False): """ >>> r = Redis() >>> r.set('a', 'pippo') 'OK' >>> try: ... r.set('a', u'pippo \u3235') ... except InvalidData, e: ... print e Error encoding unicode value for key 'a': 'ascii' codec can't encode character u'\u3235' in position 15: ordinal not in range(128). >>> r.set('b', 105.2) 'OK' >>> r.set('b', 'xxx', preserve=True) 0 >>> r.get('b') '105.2' >>> """ self.connect() # the following will raise an error for unicode values that can't be encoded to ascii # we could probably add an 'encoding' arg to init, but then what do we do with get()? # convert back to unicode? and what about ints, or pickled values? try: value = value if isinstance(value, basestring) else str(value) self._write('%s %s %s\r\n%s\r\n' % ( 'SETNX' if preserve else 'SET', name, len(value), value )) except UnicodeEncodeError, e: raise InvalidData("Error encoding unicode value for key '%s': %s." % (name, e)) return self.get_response() def get(self, name): """ >>> r = Redis() >>> r.set('a', 'pippo'), r.set('b', 15), r.set('c', '\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n'), r.set('d', '\\r\\n') ('OK', 'OK', 'OK', 'OK') >>> r.get('a') 'pippo' >>> r.get('b') '15' >>> r.get('d') '\\r\\n' >>> r.get('b') '15' >>> r.get('c') '\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n' >>> r.get('c') '\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n' >>> r.get('ajhsd') >>> """ self.connect() self._write('GET %s\r\n' % name) return self.get_response() def mget(self, *args): """ >>> r = Redis() >>> r.set('a', 'pippo'), r.set('b', 15), r.set('c', '\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n'), r.set('d', '\\r\\n') ('OK', 'OK', 'OK', 'OK') >>> r.mget('a', 'b', 'c', 'd') ['pippo', '15', '\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n', '\\r\\n'] >>> """ self.connect() self._write('MGET %s\r\n' % ' '.join(args)) return self.get_response() def incr(self, name, amount=1): """ >>> r = Redis() >>> r.delete('a') 1 >>> r.incr('a') 1 >>> r.incr('a') 2 >>> r.incr('a', 2) 4 >>> """ self.connect() if amount == 1: self._write('INCR %s\r\n' % name) else: self._write('INCRBY %s %s\r\n' % (name, amount)) return self.get_response() def decr(self, name, amount=1): """ >>> r = Redis() >>> if r.get('a'): ... r.delete('a') ... else: ... print 1 1 >>> r.decr('a') -1 >>> r.decr('a') -2 >>> r.decr('a', 5) -7 >>> """ self.connect() if amount == 1: self._write('DECR %s\r\n' % name) else: self._write('DECRBY %s %s\r\n' % (name, amount)) return self.get_response() def exists(self, name): """ >>> r = Redis() >>> r.exists('dsjhfksjdhfkdsjfh') 0 >>> r.set('a', 'a') 'OK' >>> r.exists('a') 1 >>> """ self.connect() self._write('EXISTS %s\r\n' % name) return self.get_response() def delete(self, name): """ >>> r = Redis() >>> r.delete('dsjhfksjdhfkdsjfh') 0 >>> r.set('a', 'a') 'OK' >>> r.delete('a') 1 >>> r.exists('a') 0 >>> r.delete('a') 0 >>> """ self.connect() self._write('DEL %s\r\n' % name) return self.get_response() def key_type(self, name): """ Not yet implemented. """ self.connect() self._write('TYPE %s\r\n' % name) return self.get_response() def keys(self, pattern): """ >>> r = Redis() >>> r.flush() 'OK' >>> r.set('a', 'a') 'OK' >>> r.keys('a*') ['a'] >>> r.set('a2', 'a') 'OK' >>> r.keys('a*') ['a', 'a2'] >>> r.delete('a2') 1 >>> r.keys('sjdfhskjh*') [] >>> """ self.connect() self._write('KEYS %s\r\n' % pattern) return self.get_response().split() def randomkey(self): """ >>> r = Redis() >>> r.set('a', 'a') 'OK' >>> isinstance(r.randomkey(), str) True >>> """ #raise NotImplementedError("Implemented but buggy, do not use.") self.connect() self._write('RANDOMKEY\r\n') return self.get_response() def rename(self, src, dst, preserve=False): """ >>> r = Redis() >>> try: ... r.rename('a', 'a') ... except ResponseError, e: ... print e source and destination objects are the same >>> r.rename('a', 'b') 'OK' >>> try: ... r.rename('a', 'b') ... except ResponseError, e: ... print e no such key >>> r.set('a', 1) 'OK' >>> r.rename('b', 'a', preserve=True) 0 >>> """ self.connect() if preserve: self._write('RENAMENX %s %s\r\n' % (src, dst)) return self.get_response() else: self._write('RENAME %s %s\r\n' % (src, dst)) return self.get_response().strip() def push(self, name, value, tail=False): """ >>> r = Redis() >>> r.delete('l') 1 >>> r.push('l', 'a') 'OK' >>> r.set('a', 'a') 'OK' >>> try: ... r.push('a', 'a') ... except ResponseError, e: ... print e Operation against a key holding the wrong kind of value >>> """ self.connect() # same considerations on unicode as in set() apply here try: value = value if isinstance(value, basestring) else str(value) self._write('%s %s %s\r\n%s\r\n' % ( 'LPUSH' if tail else 'RPUSH', name, len(value), value )) except UnicodeEncodeError, e: raise InvalidData("Error encoding unicode value for element in list '%s': %s." % (name, e)) return self.get_response() def llen(self, name): """ >>> r = Redis() >>> r.delete('l') 1 >>> r.push('l', 'a') 'OK' >>> r.llen('l') 1 >>> r.push('l', 'a') 'OK' >>> r.llen('l') 2 >>> """ self.connect() self._write('LLEN %s\r\n' % name) return self.get_response() def lrange(self, name, start, end): """ >>> r = Redis() >>> r.delete('l') 1 >>> r.lrange('l', 0, 1) [] >>> r.push('l', 'aaa') 'OK' >>> r.lrange('l', 0, 1) ['aaa'] >>> r.push('l', 'bbb') 'OK' >>> r.lrange('l', 0, 0) ['aaa'] >>> r.lrange('l', 0, 1) ['aaa', 'bbb'] >>> r.lrange('l', -1, 0) [] >>> r.lrange('l', -1, -1) ['bbb'] >>> """ self.connect() self._write('LRANGE %s %s %s\r\n' % (name, start, end)) return self.get_response() def ltrim(self, name, start, end): """ >>> r = Redis() >>> r.delete('l') 1 >>> try: ... r.ltrim('l', 0, 1) ... except ResponseError, e: ... print e no such key >>> r.push('l', 'aaa') 'OK' >>> r.push('l', 'bbb') 'OK' >>> r.push('l', 'ccc') 'OK' >>> r.ltrim('l', 0, 1) 'OK' >>> r.llen('l') 2 >>> r.ltrim('l', 99, 95) 'OK' >>> r.llen('l') 0 >>> """ self.connect() self._write('LTRIM %s %s %s\r\n' % (name, start, end)) return self.get_response() def lindex(self, name, index): """ >>> r = Redis() >>> res = r.delete('l') >>> r.lindex('l', 0) >>> r.push('l', 'aaa') 'OK' >>> r.lindex('l', 0) 'aaa' >>> r.lindex('l', 2) >>> r.push('l', 'ccc') 'OK' >>> r.lindex('l', 1) 'ccc' >>> r.lindex('l', -1) 'ccc' >>> """ self.connect() self._write('LINDEX %s %s\r\n' % (name, index)) return self.get_response() def pop(self, name, tail=False): """ >>> r = Redis() >>> r.delete('l') 1 >>> r.pop('l') >>> r.push('l', 'aaa') 'OK' >>> r.push('l', 'bbb') 'OK' >>> r.pop('l') 'aaa' >>> r.pop('l') 'bbb' >>> r.pop('l') >>> r.push('l', 'aaa') 'OK' >>> r.push('l', 'bbb') 'OK' >>> r.pop('l', tail=True) 'bbb' >>> r.pop('l') 'aaa' >>> r.pop('l') >>> """ self.connect() self._write('%s %s\r\n' % ('RPOP' if tail else 'LPOP', name)) return self.get_response() def lset(self, name, index, value): """ >>> r = Redis() >>> r.delete('l') 1 >>> try: ... r.lset('l', 0, 'a') ... except ResponseError, e: ... print e no such key >>> r.push('l', 'aaa') 'OK' >>> try: ... r.lset('l', 1, 'a') ... except ResponseError, e: ... print e index out of range >>> r.lset('l', 0, 'bbb') 'OK' >>> r.lrange('l', 0, 1) ['bbb'] >>> """ self.connect() try: value = value if isinstance(value, basestring) else str(value) self._write('LSET %s %s %s\r\n%s\r\n' % ( name, index, len(value), value )) except UnicodeEncodeError, e: raise InvalidData("Error encoding unicode value for element %s in list '%s': %s." % (index, name, e)) return self.get_response() def lrem(self, name, value, num=0): """ >>> r = Redis() >>> r.delete('l') 1 >>> r.push('l', 'aaa') 'OK' >>> r.push('l', 'bbb') 'OK' >>> r.push('l', 'aaa') 'OK' >>> r.lrem('l', 'aaa') 2 >>> r.lrange('l', 0, 10) ['bbb'] >>> r.push('l', 'aaa') 'OK' >>> r.push('l', 'aaa') 'OK' >>> r.lrem('l', 'aaa', 1) 1 >>> r.lrem('l', 'aaa', 1) 1 >>> r.lrem('l', 'aaa', 1) 0 >>> """ self.connect() try: value = value if isinstance(value, basestring) else str(value) self._write('LREM %s %s %s\r\n%s\r\n' % ( name, num, len(value), value )) except UnicodeEncodeError, e: raise InvalidData("Error encoding unicode value for element %s in list '%s': %s." % (index, name, e)) return self.get_response() def sort(self, name, by=None, get=None, start=None, num=None, desc=False, alpha=False): """ >>> r = Redis() >>> r.delete('l') 1 >>> r.push('l', 'ccc') 'OK' >>> r.push('l', 'aaa') 'OK' >>> r.push('l', 'ddd') 'OK' >>> r.push('l', 'bbb') 'OK' >>> r.sort('l', alpha=True) ['aaa', 'bbb', 'ccc', 'ddd'] >>> r.delete('l') 1 >>> for i in range(1, 5): ... res = r.push('l', 1.0 / i) >>> r.sort('l') ['0.25', '0.333333333333', '0.5', '1.0'] >>> r.sort('l', desc=True) ['1.0', '0.5', '0.333333333333', '0.25'] >>> r.sort('l', desc=True, start=2, num=1) ['0.333333333333'] >>> r.set('weight_0.5', 10) 'OK' >>> r.sort('l', desc=True, by='weight_*') ['0.5', '1.0', '0.333333333333', '0.25'] >>> for i in r.sort('l', desc=True): ... res = r.set('test_%s' % i, 100 - float(i)) >>> r.sort('l', desc=True, get='test_*') ['99.0', '99.5', '99.6666666667', '99.75'] >>> r.sort('l', desc=True, by='weight_*', get='test_*') ['99.5', '99.0', '99.6666666667', '99.75'] >>> r.sort('l', desc=True, by='weight_*', get='missing_*') [None, None, None, None] >>> """ stmt = ['SORT', name] if by: stmt.append("BY %s" % by) if start and num: stmt.append("LIMIT %s %s" % (start, num)) if get is None: pass elif isinstance(get, basestring): stmt.append("GET %s" % get) elif isinstance(get, list) or isinstance(get, tuple): for g in get: stmt.append("GET %s" % g) else: raise RedisError("Invalid parameter 'get' for Redis sort") if desc: stmt.append("DESC") if alpha: stmt.append("ALPHA") self.connect() self._write(' '.join(stmt + ["\r\n"])) return self.get_response() def sadd(self, name, value): """ >>> r = Redis() >>> res = r.delete('s') >>> r.sadd('s', 'a') 1 >>> r.sadd('s', 'b') 1 >>> """ self.connect() # same considerations on unicode as in set() apply here try: value = value if isinstance(value, basestring) else str(value) self._write('SADD %s %s\r\n%s\r\n' % ( name, len(value), value )) except UnicodeEncodeError, e: raise InvalidData("Error encoding unicode value for element in set '%s': %s." % (name, e)) return self.get_response() def srem(self, name, value): """ >>> r = Redis() >>> r.delete('s') 1 >>> r.srem('s', 'aaa') 0 >>> r.sadd('s', 'b') 1 >>> r.srem('s', 'b') 1 >>> r.sismember('s', 'b') 0 >>> """ self.connect() # same considerations on unicode as in set() apply here try: value = value if isinstance(value, basestring) else str(value) self._write('SREM %s %s\r\n%s\r\n' % ( name, len(value), value )) except UnicodeEncodeError, e: raise InvalidData("Error encoding unicode value for element in set '%s': %s." % (name, e)) return self.get_response() def sismember(self, name, value): """ >>> r = Redis() >>> r.delete('s') 1 >>> r.sismember('s', 'b') 0 >>> r.sadd('s', 'a') 1 >>> r.sismember('s', 'b') 0 >>> r.sismember('s', 'a') 1 >>> """ self.connect() # same considerations on unicode as in set() apply here try: value = value if isinstance(value, basestring) else str(value) self._write('SISMEMBER %s %s\r\n%s\r\n' % ( name, len(value), value )) except UnicodeEncodeError, e: raise InvalidData("Error encoding unicode value for element in set '%s': %s." % (name, e)) return self.get_response() def sinter(self, *args): """ >>> r = Redis() >>> res = r.delete('s1') >>> res = r.delete('s2') >>> res = r.delete('s3') >>> r.sadd('s1', 'a') 1 >>> r.sadd('s2', 'a') 1 >>> r.sadd('s3', 'b') 1 >>> try: ... r.sinter() ... except ResponseError, e: ... print e wrong number of arguments >>> try: ... r.sinter('l') ... except ResponseError, e: ... print e Operation against a key holding the wrong kind of value >>> r.sinter('s1', 's2', 's3') set([]) >>> r.sinter('s1', 's2') set(['a']) >>> """ self.connect() self._write('SINTER %s\r\n' % ' '.join(args)) return set(self.get_response()) def sinterstore(self, dest, *args): """ >>> r = Redis() >>> res = r.delete('s1') >>> res = r.delete('s2') >>> res = r.delete('s3') >>> r.sadd('s1', 'a') 1 >>> r.sadd('s2', 'a') 1 >>> r.sadd('s3', 'b') 1 >>> r.sinterstore('s_s', 's1', 's2', 's3') 'OK' >>> r.sinterstore('s_s', 's1', 's2') 'OK' >>> r.smembers('s_s') set(['a']) >>> """ self.connect() self._write('SINTERSTORE %s %s\r\n' % (dest, ' '.join(args))) return self.get_response() def smembers(self, name): """ >>> r = Redis() >>> r.delete('s') 1 >>> r.sadd('s', 'a') 1 >>> r.sadd('s', 'b') 1 >>> try: ... r.smembers('l') ... except ResponseError, e: ... print e Operation against a key holding the wrong kind of value >>> r.smembers('s') set(['a', 'b']) >>> """ self.connect() self._write('SMEMBERS %s\r\n' % name) return set(self.get_response()) def select(self, db): """ >>> r = Redis() >>> r.delete('a') 1 >>> r.select(1) 'OK' >>> r.set('a', 1) 'OK' >>> r.select(0) 'OK' >>> r.get('a') >>> """ self.connect() self._write('SELECT %s\r\n' % db) return self.get_response() def move(self, name, db): """ >>> r = Redis() >>> r.select(0) 'OK' >>> r.set('a', 'a') 'OK' >>> r.select(1) 'OK' >>> if r.get('a'): ... r.delete('a') ... else: ... print 1 1 >>> r.select(0) 'OK' >>> r.move('a', 1) 1 >>> r.get('a') >>> r.select(1) 'OK' >>> r.get('a') 'a' >>> r.select(0) 'OK' >>> """ self.connect() self._write('MOVE %s %s\r\n' % (name, db)) return self.get_response() def save(self, background=False): """ >>> r = Redis() >>> r.save() 'OK' >>> try: ... resp = r.save(background=True) ... except ResponseError, e: ... assert str(e) == 'background save already in progress', str(e) ... else: ... assert resp == 'OK' >>> """ self.connect() if background: self._write('BGSAVE\r\n') else: self._write('SAVE\r\n') return self.get_response() def lastsave(self): """ >>> import time >>> r = Redis() >>> t = int(time.time()) >>> r.save() 'OK' >>> r.lastsave() >= t True >>> """ self.connect() self._write('LASTSAVE\r\n') return self.get_response() def flush(self, all_dbs=False): """ >>> r = Redis() >>> r.flush() 'OK' >>> r.flush(all_dbs=True) 'OK' >>> """ self.connect() self._write('%s\r\n' % ('FLUSHALL' if all_dbs else 'FLUSHDB')) return self.get_response() def info(self): """ >>> r = Redis() >>> info = r.info() >>> info and isinstance(info, dict) True >>> isinstance(info.get('connected_clients'), int) True >>> """ self.connect() self._write('INFO\r\n') info = dict() for l in self.get_response().split('\r\n'): if not l: continue k, v = l.split(':', 1) info[k] = int(v) if v.isdigit() else v return info def get_response(self): data = self._read().strip() c = data[0] if c == '-': raise ResponseError(data[5:] if data[:5] == '-ERR ' else data[1:]) if c == '+': return data[1:] if c == '*': try: num = int(data[1:]) except (TypeError, ValueError): raise InvalidResponse("Cannot convert multi-response header '%s' to integer" % data) result = list() for i in range(num): result.append(self._get_value()) return result return self._get_value(data) def _get_value(self, data=None): data = data or self._read().strip() if data == '$-1': return None try: c, i = data[0], (int(data[1:]) if data.find('.') == -1 else float(data[1:])) except ValueError: raise InvalidResponse("Cannot convert data '%s' to integer" % data) if c == ':': return i if c != '$': raise InvalidResponse("Unkown response prefix for '%s'" % data) buf = [] while i > 0: data = self._read() i -= len(data) if len(data) > i: # we got the ending crlf data = data.rstrip() buf.append(data) if i == 0: # the data has a trailing crlf embedded, let's restore it buf.append(self._read()) return ''.join(buf) def disconnect(self): if isinstance(self._sock, socket.socket): try: self._sock.close() except socket.error: pass self._sock = None self._fp = None def connect(self): """ >>> r = Redis() >>> r.connect() >>> isinstance(r._sock, socket.socket) True >>> """ if isinstance(self._sock, socket.socket): return try: sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.connect((self.host, self.port)) except socket.error, e: raise ConnectionError("Error %s connecting to %s:%s. %s." % (e.args[0], self.host, self.port, e.args[1])) else: self._sock = sock self._fp = self._sock.makefile('r') if __name__ == '__main__': import doctest doctest.testmod()